Dear Jafar

for Newtonian or nonNewtonian problems :

you copy and paste this text to controlDict to write forces in one text file and you can plot it in excell soon.

forceCoeffsCyl

{

         // rhoInf - reference density

        // CofR - Centre of rotation

        // dragDir - Direction of drag coefficient

       // liftDir - Direction of lift coefficient

       // pitchAxis - Pitching moment axis

      // magUinf - free stream velocity magnitude

      // lRef - reference length

     // Aref - reference area

type forceCoeffs;

functionObjectLibs ("libforces.so");

        patches ("patchnames");

      pName p;

      Uname U;

      rhoName rhoInf;

      rhoInf 1.0;

//// Dump to file

log true;

       CofR (0.0 0 0);

      liftDir (0 1 0);

     dragDir (1 0 0);

     pitchAxis (0 0 1);

     magUInf 1.0;

     lRef 1.0; // reference enght

     Aref 1.0; // reference area 1 for 2d

    outputControl timeStep;

      outputInterval 1;

}

thanx Dear Abdul aziz Jaafar

Dear Abas

Thanks for your reply,

i am working on creeping flow around cylinder between two plate for Bingham fluid(non-Newtonian),what should i specify  for rhoInf  ,i also need to know what is the density .how can i find it?

Best regards

Jafar

Dear Abbas

I have used the statement as you said, but do you know how openfoam calculate force on pile with this statement? is it total force on total area or unit of height ?

thank you in advance,

mohammad

Dear All,

For the new version of OpenFOAM 4.1, the name rhoName should be changes to rho.

......

rho rhoInf;

......

Dear all

I have the same problem! I want to calculate Cd for viscoelastic fluid flow around a cylinder with openFoam. but probabely I should make some changes on forces.C code! could you please help me if you have this experience?

Thanks